J. P. Genet, S. Mallart, C. Pinel, S. Juge, and J. A. Laffitte, Tet. Assym., 1991, vol. 2, p. 43, report reaction of (COD)Ru(2-methallyl).sub.2 with chiral bidentate phosphines to give Ru(P-P)(2-methylallyl).sub.2 complexes which, under hydrogen, catalyzed hydrogenation of olefins. The ruthenium complexes produced under hydrogen were not isolated or characterized.
B. Chaudret and R. Poilblanc, Organometallics, 1985, vol. 4, p. 1722, describe hydrogenation of the Ru(0) olefin complex, Ru(COD)(COT), in the presence of tricyclohexylphosphine to give RuH.sub.2 (H.sub.2).sub.2 (PCy.sub.3).sub.2.
J. Powell and B. L. Shaw, J. Chem. Soc. (A), 1968, p. 159, describe the preparation of allylic complexes of ruthenium(II), Ru(all).sub.2 (diolefin), where all=allyl or 2-methylallyl and diolefin=norbomadiene or 1,5-cyclooctadiene.
M. Cooke, R. J. Goodfellow, M. Green, and G. Parker, J. Chem. Soc.(A), 1971, p. 16 describe reaction of cyclooctadiene mthenium bis(methylallyl) with phosphorus ligands to give (P ligand).sub.2 Ru(2-methylallyl).sub.2.
W. H. Knoth, U.S. Pat. No. 3,538,133, describes preparation of RuH.sub.2 (Q2)(PPh3).sub.3, wherein Q is H or N, and some other closely related ruthenium complexes by reaction of RuHCI(PPh.sub.3).sub.3 with triethylaluminum or sodium borohydride. However, the methods used to prepare the required RuHCI(PPh.sub.3).sub.3 starting material are only applicable for closely related triarylphosphines, therefore the chemistry described by Knoth is not broadly applicable to a wide range of PR.sub.3 ligands.